Bald eagleAverage clutch size: 1-3 eggs Cool! Measuring six feet across and four feet tall (or even larger!), bald-eagle nests are some of the largest of any avian species.

These birds, the symbol of the United States, mate for life unless one of the two dies. Their spectacular courtship rituals are a sight to see, with the birds locking talons, then flipping, spinning, and twirling through the air in a maneuver called a Cartwheel Display. They break apart seemingly at the last moment, just before hitting the ground. For more: Audubon and Cornell’s All About Birds

Photo: USFWS

Laysan albatrossAverage clutch size: 1 eggCool! Nearly three-quarters of the world’s population of this species nests on Midway Atoll National Wildlife Refuge.

Laysan albatrosses, which don’t breed until they’re eight or nine years old, are monogamous, annually solidifying their bond through ritual dancing. “If they do lose their mate, they will go through a year or two of a mourning period,” says John Klavitter, U.S. Fish and Wildlife Service biologist at Midway Atoll. “After that, they will do a courtship dance to try to find another mate.” For more: Midway Atoll National Wildlife Refuge and Birds of Midway Atoll

Mute swanAverage clutch size: 5-7 eggsCool! During mating, the black knob at the base of a male’s bill swells up on these extremely territorial birds originally introduced from Europe.

Mute swan pairs reportedly stay together for life. However, divorce does occur in less than 3% of mates that breed successfully and 9% that don’t. They re-mate when a partner dies; how quickly this happens depends on the survivor’s gender. Females find a new male within as few as three weeks. Males, however, tend to wait until the following fall or winter—allowing time to defend their nests and finish raising their cygnets. For more:Cornell’s All About Birds

Scarlet macawAverage clutch size: 2-4 eggsCool! These birds can live to be 75 years old in captivity or, on average, 33 years old in the wild.

Typically these rainbow-colored birds spend their lives together. They even preen each other and their young, picking bugs from their feathers. Scarlet macaw parents, which reach sexual maturity sometime between age three and four, won’t raise new chicks until their previous ones have fledged and are independent. For more:Rainforest Alliance and University of Michigan Museum of Zoology

Photo: USFWS

Whooping craneAverage clutch size: 2 eggsCool! Not surprisingly (when you get a look at the legs), this crane species is the tallest bird in North America.

Talk about a mating dance, whooping cranes—which are monogamous and mate for life—bow their heads, flap their wings, leap and bounce off stiffened legs all in the effort to secure a partner. This pairing off usually happens when the birds—which are red on Audubon’s Watchlist—are between two and three years old. For more: Audubon species profiles

Photo: Bookis, Creative Commons license

California condorAverage clutch size: 1 egg Cool! When a golden eagle is around, this condor species—normally the dominant scavenger—will leave the carcass for the other bird and its seriously strong talons.

It takes California condors, highly endangered birds on Audubon’s Watchlist, between six and eight years to reach sexual maturity. Once the birds mate, they stay together for years if not for life. During courtship, aerial displays bring the pairs to several nest options—kind of like searching for a potential home. The female, of course, has the final say in where the birds settle down. For more:Cornell’s All About Birds and Audubon species profiles

Atlantic puffinAverage clutch size: 1 eggCool! Puffins can fly up to 55 miles per hour, flapping their wings 400 times per minute.

These pigeon-sized “clowns of the sea” don’t breed until they’re between three and six years old. Once they do, however, they stick with their partners for good, returning to the same burrow each season, sharing egg-incubating and parenting duties, even performing what’s known as billing, during which the birds rub together their beaks. For more: Project Puffin

Black vultureAverage clutch size: 2 eggsCool! This vulture species doesn’t build a nest, but rather lays its eggs on the ground or in hollow cavities.

Yes, even black vultures stick together. “One bird, presumed to be male, chases a presumed female through the air and periodically dives at her” as part of the mating ritual, according to Birds of North America online. They form such a tight bond, in fact, that they hang out year round—not just during breeding season. For more: Cornell’s All About Birds